EP0784501B1 - Dewatering process - Google Patents
Dewatering process Download PDFInfo
- Publication number
- EP0784501B1 EP0784501B1 EP95932099A EP95932099A EP0784501B1 EP 0784501 B1 EP0784501 B1 EP 0784501B1 EP 95932099 A EP95932099 A EP 95932099A EP 95932099 A EP95932099 A EP 95932099A EP 0784501 B1 EP0784501 B1 EP 0784501B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- belt
- electrically conductive
- conductive material
- sludge
- dewatering process
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
- B01D61/56—Electro-osmotic dewatering
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/006—Electrochemical treatment, e.g. electro-oxidation or electro-osmosis
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/121—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering
- C02F11/123—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering using belt or band filters
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/14—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents
- C02F11/147—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents using organic substances
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/15—Treatment of sludge; Devices therefor by de-watering, drying or thickening by treatment with electric, magnetic or electromagnetic fields; by treatment with ultrasonic waves
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/469—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
Definitions
- the present invention relates to a dewatering process and to a belt for use in the dewatering process.
- Waste sludge typically has a very low solids content (less than 10 wt. % - the rest being water), so it makes sense to reduce the weight and volume by lowering the water content.
- Traditional gravitational techniques such as sedimentation or flotation are slow and can only achieve maximum solids content in the order of 12 wt. %.
- More recent methods include the use of chamber filter presses, wire belt presses and centrifugal techniques. The former requires a large amount of flocculating agent to be added, whilst the latter two are restricted by the relatively low dwell time of the sludge in the dewatering areas.
- Japanese Patent Application JP-A-59036507 describes a dewatering apparatus wherein sludge is fed into a space between upper and lower endless belts, the upper belt being made as a plate-like conductive belt, and the lower belt is constituted by a filter cloth and a conductive net or porous plate integrally attached to its underside or a conductive filter medium.
- the upper and lower belts are run at the same speed as the linear transfer speed of the sludge in the forward flow direction of the sludge, while DC voltage is applied.
- the dewatered sludge is removed from the belts by scrapers at the outlet side, and the space between the belts becomes narrower in the flow direction of the sludge.
- the object of the invention is to provide a still more efficient means of dewatering sludges so as to provide an increase of solids content in the end product.
- a sludge dewatering process in which a sludge product comprising water and other materials is subjected to compressive mechanical forces and electro-osmosis using a belt comprising, at least in part, electrically conductive material, wherein the belt comprises a plurality of spiral yarns joined by hinge wires and wherein the said electrically conductive material is inserted into and/or onto the said spiral yarns.
- the belt may wholly comprise electrically conductive material.
- the mechanical and electro-osmosis techniques preferably take place simultaneously.
- the process according to the invention is particularly useful for the dewatering of sludges and slurries produced by water purification plants, metal processing and galvanising installations and factory farms.
- a conditioning (floccing) agent is added to coagulate the fine particles by neutralising the ionic charges and thereby eliminate electro-static repulsion.
- These are typically high molecular weight, water-insoluble synthetic polymers containing charged groups.
- Particularly preferred are SUPERFLOC A-130 (Trade Mark), an anionic polyacrylamide having a molecular weight of 6,000,000 - 8,000,000 or SYNTHOFLOC 8022 H-PWG (Trade Mark).
- Cationic polyelectrolytes may also be used. Since the addition of floccing agents will lead to an increase in the surface charge and therefore an increased zeta potential, the amount added must not be too great.
- substantially 4 kg of floccing agent is used per metric tonne sludge.
- the potential difference applied is preferably no greater than 30 V and the electrical current is preferably no greater than 120 A.
- a filter belt for use in a sludge dewatering process in which a sludge product comprising water and other materials is subjected to compressive mechanical forces and electro-osmosis, the said belt comprising, at least in part, electrically conductive material, wherein the belt comprises a plurality of spiral yarns joined by hinge wires and the said electrically conductive material is inserted into and/or onto the said spiral yarns.
- the filter belt used in the dewatering process preferably comprises polyester and/or polyamide spirals. Any conducting material may be inserted into and/or onto the base material of the belt.
- the conducting material preferably comprises at least one strip or braided yarn.
- Preferred materials include steel, copper or carbon which preferably extend through the belt.
- Electrically conductive staple fibre, especially tinned copper, may also be secured to one or both sides of the fabric, preferably by needling to ensure contact with the insert.
- the base material may be a link belt of the type described in EP 0028630.
- the spiral fibres comprise a multiplicity of helical coils joined in side-by-side disposition by hinge wires of a thermo-plastic monofilament material threaded through the interdigitated turns of adjacent coils.
- the resultant link structure is subjected to a suitable heat setting temperature and longitudinal tension to cause the hinge wires to deform and assume a crimped configuration in the plane of the structure.
- the hinge wires extend in the cross machine direction of the belt.
- Conductive material is located within each coil intermediate the interdigitating sections of that coil with adjacent coils,
- the conductive material preferably comprises conducting wires or strips extending in the cross machine direction.
- Conductive staple fibres may be needled to one or both sides of the belt.
- sludge such as that produced by the addition of polyaluminium chlorides to drinking water in a purification plant, is pumped to a polymeric flocculation agent/sludge mixing vessel 11 for flocculation.
- the flocculated sludge is applied directly to a first pre-dewatering belt 12 whereupon a large proportion of the water drains away under gravity.
- the pre-dewaterised sludge undergoes a second similar pre-dewatering on another belt 13 before entering the press zone 14.
- the sludge is transported between two belts 13,15, at least one of which being porous, and an increasing excessive force is applied to the sludge bed.
- the dewatered sludge is finally removed from the belts using scrapers and the belts are rinsed in a cleaning installation.
- Stainless steel cathodes are incorporated at various points in the cycle. In the press section, however, no such electrodes are used. Instead the press belt comprises a polyester spiral fabric having all the synthetic polymer stuffer yarns located in the coils replaced with one or more metal strips or yarns. The metal strips or yarns, which are charged by way of a wiper 16, serve to act as a cathode, while the carbon steel press rollers act as alternate anodes and cathodes. These rollers may optionally be coated.
- Figs. 2 and 3 show one of the press belts of Fig.1
- the belt comprises a multiplicity of individual coils 16 of monofilament polyester material arranged in interdigitated side-by-side disposition, adjacent coils being connected together by respective hinge wires 17 threaded through the tunnels formed by such interdigitated coils 16. Adjacent coils 16 are of opposite hand.
- the hinge wires 17 are deformed into a crimped appearance and the end regions of the individual turns are deformed.
- the structure is set by subjecting the fabric, when under tension, to a suitable heat setting temperature for the material, thus to impart dimensional stability to the fabric.
- Two conducting wires 18 are inserted in each coil intermediate the interdigitating portions of that coil with adjacent coils. Staple wire fibres 19 are then needled to the upper surface and optionally the lower surface of the belt.
- the belt provides the necessary conductive elements for electro-osmosis while at the same time being relatively simple to produce and easy to clean.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Water Supply & Treatment (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Mechanical Engineering (AREA)
- Urology & Nephrology (AREA)
- Health & Medical Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Electromagnetism (AREA)
- Physics & Mathematics (AREA)
- Electrochemistry (AREA)
- Treatment Of Sludge (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Extraction Or Liquid Replacement (AREA)
- Filtering Materials (AREA)
- Fertilizers (AREA)
- Processing Of Solid Wastes (AREA)
- Water Treatment By Sorption (AREA)
- Centrifugal Separators (AREA)
- External Artificial Organs (AREA)
- Woven Fabrics (AREA)
- Filtration Of Liquid (AREA)
- Water Treatment By Electricity Or Magnetism (AREA)
Abstract
Description
- The present invention relates to a dewatering process and to a belt for use in the dewatering process.
- In any industrialised country there currently exists the problem of the disposal of the vast and ever increasing amounts of sludge produced during the purification of drinking water and sewage and the dredging of waterways such as harbours, canals and drainage channels. Some sludge may be used as a fertiliser or landfill material, or may be incinerated, but the largest proportion of waste sludge must be dumped due to its contaminated nature, particularly where it has been recovered from areas of significant industrial activity. As the price for disposal of sludge rises so does the need to reduce the sludge weight and volume, in order to lower both dumping and transport costs.
- Waste sludge typically has a very low solids content (less than 10 wt. % - the rest being water), so it makes sense to reduce the weight and volume by lowering the water content. Traditional gravitational techniques such as sedimentation or flotation are slow and can only achieve maximum solids content in the order of 12 wt. %. More recent methods include the use of chamber filter presses, wire belt presses and centrifugal techniques. The former requires a large amount of flocculating agent to be added, whilst the latter two are restricted by the relatively low dwell time of the sludge in the dewatering areas. All are particularly unsuitable for fine, highly colloidal sludges, where a significant proportion of the solid particles can not be retained without the use of A much finer filter medium, thereby lowering the permeability of the sludge bed and leading to maximum achievable solids content of about 15 wt. % for such sludge types.
- The use of electro-osmosis as a dewatering technique is described in DE 12450g. A material is dispersed in a polar solution having a charged surface. Therefore the electrolyte in the immediate vicinity of the charged surface possesses a net excess opposite charge due to the electro-static attraction forces of the ions of opposed polarity. In the region of the charged surface a so-called diffuse double layer is formed, whereby some of the ions are firmly bonded at said surface and are removed from the equilibrium arising from the tendency of particles in the highly concentrated surface region of the liquid to diffuse into the less concentrated bulk interior. This results in a concentration gradient of ions which drops off rapidly away from the charged surface. In order for these firmly bonded ions to become mobile once again, a potential needs to be applied - the so-called zeta potential. By keeping the sludge matrix between the electrodes, the rate of dewatering at the cathode will be accelerated upon the application of an electric field corresponding to at least the value of the zeta potential, since the ions are then able to move freely to and from the disperse phase.
- Japanese Patent Application JP-A-59036507 describes a dewatering apparatus wherein sludge is fed into a space between upper and lower endless belts, the upper belt being made as a plate-like conductive belt, and the lower belt is constituted by a filter cloth and a conductive net or porous plate integrally attached to its underside or a conductive filter medium. The upper and lower belts are run at the same speed as the linear transfer speed of the sludge in the forward flow direction of the sludge, while DC voltage is applied. The dewatered sludge is removed from the belts by scrapers at the outlet side, and the space between the belts becomes narrower in the flow direction of the sludge.
- The effectiveness of mechanical dewatering techniques is dependent upon the permeability of the medium to be dewatered, since the applied force (pressure for wire belt or chamber filter presses, gravitational acceleration for decanter centrifuges) compacts the bed of material particles. Hence the porosity of the bed is reduced and therefore the flow of water from the bed is reduced. For electro-osmosis the liquid flow is independent of the bed porosity. Here it is the electrical conductivity of said disperse phase that is the key factor and therefore low bed porosities will not reduce the effectiveness of water removal. Dewatering times can be reduced with respect to mechanical techniques by applying a potential difference across the sludge bed. This reduction in time results in a net energy saving.
- The object of the invention is to provide a still more efficient means of dewatering sludges so as to provide an increase of solids content in the end product.
- According to a first aspect of the present invention there is provided a sludge dewatering process in which a sludge product comprising water and other materials is subjected to compressive mechanical forces and electro-osmosis using a belt comprising, at least in part, electrically conductive material, wherein the belt comprises a plurality of spiral yarns joined by hinge wires and wherein the said electrically conductive material is inserted into and/or onto the said spiral yarns.
- The belt may wholly comprise electrically conductive material.
- The mechanical and electro-osmosis techniques preferably take place simultaneously.
- The combination of electro-osmosis and mechanical dewatering techniques leads to a faster, low energy consumption process whereby higher solids contents are achievable than with electro-osmotic or mechanical methods alone.
- The process according to the invention is particularly useful for the dewatering of sludges and slurries produced by water purification plants, metal processing and galvanising installations and factory farms.
- In order to increase the particle size of fine colloidal sludges it is preferred that a conditioning (floccing) agent is added to coagulate the fine particles by neutralising the ionic charges and thereby eliminate electro-static repulsion. These are typically high molecular weight, water-insoluble synthetic polymers containing charged groups. Particularly preferred are SUPERFLOC A-130 (Trade Mark), an anionic polyacrylamide having a molecular weight of 6,000,000 - 8,000,000 or SYNTHOFLOC 8022 H-PWG (Trade Mark). Cationic polyelectrolytes may also be used. Since the addition of floccing agents will lead to an increase in the surface charge and therefore an increased zeta potential, the amount added must not be too great. Preferably substantially 4 kg of floccing agent is used per metric tonne sludge.
- The potential difference applied is preferably no greater than 30 V and the electrical current is preferably no greater than 120 A.
- According to a second aspect of the present invention there is provided a filter belt for use in a sludge dewatering process in which a sludge product comprising water and other materials is subjected to compressive mechanical forces and electro-osmosis, the said belt comprising, at least in part, electrically conductive material, wherein the belt comprises a plurality of spiral yarns joined by hinge wires and the said electrically conductive material is inserted into and/or onto the said spiral yarns.
- The filter belt used in the dewatering process preferably comprises polyester and/or polyamide spirals. Any conducting material may be inserted into and/or onto the base material of the belt. The conducting material preferably comprises at least one strip or braided yarn. Preferred materials include steel, copper or carbon which preferably extend through the belt. Electrically conductive staple fibre, especially tinned copper, may also be secured to one or both sides of the fabric, preferably by needling to ensure contact with the insert.
- The base material may be a link belt of the type described in EP 0028630. The spiral fibres comprise a multiplicity of helical coils joined in side-by-side disposition by hinge wires of a thermo-plastic monofilament material threaded through the interdigitated turns of adjacent coils. The resultant link structure is subjected to a suitable heat setting temperature and longitudinal tension to cause the hinge wires to deform and assume a crimped configuration in the plane of the structure.
- The hinge wires extend in the cross machine direction of the belt. Conductive material is located within each coil intermediate the interdigitating sections of that coil with adjacent coils, The conductive material preferably comprises conducting wires or strips extending in the cross machine direction. Conductive staple fibres may be needled to one or both sides of the belt.
- In order that the present invention may be more readily understood a specific embodiment thereof will now be described by way of example only with reference to the accompanying drawings in which:-
- Fig.1 is a schematic diagram of the process of the invention;
- Fig.2 is a plan view of the dewatering belt used in the process of Fig. 1; and
- Fig.3 is an underplan view of the belt of Fig.2.
-
- Referring to Fig.1, sludge such as that produced by the addition of polyaluminium chlorides to drinking water in a purification plant, is pumped to a polymeric flocculation agent/
sludge mixing vessel 11 for flocculation. The flocculated sludge is applied directly to a first pre-dewatering belt 12 whereupon a large proportion of the water drains away under gravity. The pre-dewaterised sludge undergoes a second similar pre-dewatering on anotherbelt 13 before entering thepress zone 14. Herein the sludge is transported between twobelts wiper 16, serve to act as a cathode, while the carbon steel press rollers act as alternate anodes and cathodes. These rollers may optionally be coated. - Figs. 2 and 3 show one of the press belts of Fig.1 The belt comprises a multiplicity of
individual coils 16 of monofilament polyester material arranged in interdigitated side-by-side disposition, adjacent coils being connected together by respective hinge wires 17 threaded through the tunnels formed by such interdigitated coils 16.Adjacent coils 16 are of opposite hand. The hinge wires 17 are deformed into a crimped appearance and the end regions of the individual turns are deformed. The structure is set by subjecting the fabric, when under tension, to a suitable heat setting temperature for the material, thus to impart dimensional stability to the fabric. - Two conducting
wires 18 are inserted in each coil intermediate the interdigitating portions of that coil with adjacent coils.Staple wire fibres 19 are then needled to the upper surface and optionally the lower surface of the belt. The belt provides the necessary conductive elements for electro-osmosis while at the same time being relatively simple to produce and easy to clean. - The use of the dewatering belt described above in lieu of a conventional belt reduces the overall dewatering cost per m3 of water removed by approximately 27% and the cost per tonne of dry cake obtained by approximately 46%. These cost reductions, which take into account the additional fabric production costs and additional power requirements, result from the lower dumping costs of the dewatered product and reduced belt contamination.
- It is to be understood that the above described embodiment is by way of illustration only. Many modifications and variations are possible.
Claims (12)
- A sludge dewatering process in which a sludge product comprising water and other materials is subjected to compressive mechanical forces and electro-osmosis using a belt (12) comprising, at least in part, electrically conductive material, characterised in that the belt (12) comprises a plurality of spiral yarns (16) joined by hinge wires (17) and wherein the said electrically conductive material (18) is inserted into and/or onto the said spiral yarns (16).
- A dewatering process as claimed in claim 1, wherein the product is simultaneously subjected to said compressive mechanical forces and electro-osmosis.
- A dewatering process as claimed in claim 1 or claim 2, wherein a floccing agent is added to the product.
- A dewatering process as claimed in any preceding claim, wherein a potential difference of no greater than 30 V is applied across the belt (12).
- A dewatering process as claimed in any preceding claim, wherein an electric current no greater than 120 A flows through the electrically conductive material (18) of the belt (12).
- A dewatering process as claimed in claim 5, wherein the electrically conductive material (18) comprises steel, copper or carbon.
- A dewatering process as claimed in claim 5 or claim 6, wherein at least some of the electrically conductive material (18) consists of electrically conductive staple fibre (19).
- A dewatering process as claimed in any preceding claim, wherein at least some of the electrically conductive material (18) is in the form of wires or strips (18) extending in the cross machine direction of the belt (12).
- A filter belt for use in a sludge dewatering process in which a sludge product comprising water and other materials is subjected to compressive mechanical forces and electro-osmosis, said belt (12) comprising, at least in part, electrically conductive material (18), characterised in that the belt (12) comprises a plurality of spiral yarns (16) joined by hinge wires (17) and the said electrically conductive material (18) is inserted into and/or onto the said spiral yarns (16).
- A filter belt as claimed in claim 9, wherein the electrically conductive material (18) comprises steel, copper or carbon.
- a filter belt as claimed in claim 9 or claim 10, wherein at least some of the electrically conductive material (18) consists of electrically conductive staple fibre (19).
- A filter belt as claimed in any of claims 9 to 11, wherein at least some of the electrically conductive material (18) is in the form of wires or strips (18) extending in the cross-machine direction of the belt (12).
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9420216 | 1994-10-06 | ||
GB9420216A GB9420216D0 (en) | 1994-10-06 | 1994-10-06 | Dewatering process |
PCT/GB1995/002255 WO1996011051A2 (en) | 1994-10-06 | 1995-09-22 | Dewatering process |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0784501A2 EP0784501A2 (en) | 1997-07-23 |
EP0784501B1 true EP0784501B1 (en) | 1999-12-01 |
Family
ID=10762479
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP95932099A Expired - Lifetime EP0784501B1 (en) | 1994-10-06 | 1995-09-22 | Dewatering process |
Country Status (13)
Country | Link |
---|---|
US (1) | US5891342A (en) |
EP (1) | EP0784501B1 (en) |
JP (1) | JPH10506839A (en) |
KR (1) | KR970706055A (en) |
CN (1) | CN1076629C (en) |
AT (1) | ATE187097T1 (en) |
AU (1) | AU3528595A (en) |
BR (1) | BR9509034A (en) |
CA (1) | CA2199389A1 (en) |
DE (1) | DE69513675T2 (en) |
FI (1) | FI971426A0 (en) |
GB (1) | GB9420216D0 (en) |
WO (1) | WO1996011051A2 (en) |
Families Citing this family (30)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100330516B1 (en) * | 1999-02-23 | 2002-03-28 | 김영대 | Filtration apparatus having belt press used synthetic fiber thread |
AU2001254528B2 (en) * | 2000-05-10 | 2004-10-07 | Crc For Waste Management & Pollution Control Limited | Apparatus for electrodewatering |
AUPQ741800A0 (en) * | 2000-05-10 | 2000-06-01 | Commonwealth Scientific And Industrial Research Organisation | Apparatus for electrodewatering by filtration |
AU2003206513A1 (en) | 2002-02-12 | 2003-09-04 | Les Technologies Elcotech Inc. | Method for the treatment of slurries by the combined action of pressure and electro-osmosis |
CA2437245A1 (en) * | 2003-08-11 | 2005-02-11 | Les Technologies Elcotech Inc. | Apparatus for treating high dryness sludge |
GB0323068D0 (en) | 2003-10-01 | 2003-11-05 | Nuground Ltd | Dewatering treatment system and method |
US20050124247A1 (en) * | 2003-11-24 | 2005-06-09 | Billings Alan L. | Metal spiral fabrics for corrugator machines |
GB0329546D0 (en) * | 2003-12-19 | 2004-01-28 | Nuground Ltd | Waste dewatering treatmwnt system and method |
KR20090027602A (en) * | 2006-06-14 | 2009-03-17 | 레스 테크놀로지스 엘코테크 인코포레이션 | Processes and apparatuses for treating and/or increasing dryness of a substance |
JP2008212909A (en) * | 2007-02-28 | 2008-09-18 | Koa Gijutsu Kk | Electroosmotic dehydration apparatus |
KR100860979B1 (en) * | 2007-05-14 | 2008-09-30 | 주식회사 삼우인텍 | The electroosmotic dehydrator |
KR100812821B1 (en) * | 2007-09-28 | 2008-03-12 | 박경득 | Dehydrator |
CN101224943B (en) * | 2008-02-01 | 2010-09-08 | 陈江涛 | Container type electroosmosis sludge soil reproducing method and device thereof |
CN102361829B (en) * | 2009-03-30 | 2013-07-24 | 栗田工业株式会社 | Method for dewatering sludge and method and device for electroosmotic dewatering |
CN101525210B (en) * | 2009-04-02 | 2011-01-05 | 浙江华章科技有限公司 | Burr type electrode applied to electroosmotic dehydration |
US8772004B2 (en) * | 2009-06-25 | 2014-07-08 | Old Dominion University Research Foundation | System and method for high-voltage pulse assisted aggregation of algae |
CN102060427B (en) * | 2010-12-09 | 2014-12-17 | 宜兴能达环保科技有限公司 | Electroosmosis dewatering method and device of water-containing material |
US9447540B2 (en) | 2011-05-13 | 2016-09-20 | Stora Enso Oyj | Process for treating microfibrillated cellulose and microfibrillated cellulose treated according to the process |
KR101070296B1 (en) * | 2011-06-27 | 2011-10-06 | 주식회사 화인 | Drum type electro-osmosis dehydrator for saving electric |
GB2498922A (en) | 2011-12-14 | 2013-08-07 | Madison Filter 981 Ltd | Antistatic link belt |
WO2013103921A1 (en) * | 2012-01-05 | 2013-07-11 | Bay Materials Llc | Electrochemical methods and products |
US8709258B2 (en) | 2012-07-12 | 2014-04-29 | Heliae Development, Llc | Patterned electrical pulse microorganism aggregation |
US8702991B2 (en) | 2012-07-12 | 2014-04-22 | Heliae Development, Llc | Electrical microorganism aggregation methods |
US8668827B2 (en) | 2012-07-12 | 2014-03-11 | Heliae Development, Llc | Rectangular channel electro-acoustic aggregation device |
US8709250B2 (en) | 2012-07-12 | 2014-04-29 | Heliae Development, Llc | Tubular electro-acoustic aggregation device |
US8673154B2 (en) | 2012-07-12 | 2014-03-18 | Heliae Development, Llc | Tunable electrical field for aggregating microorganisms |
CN103253844A (en) * | 2013-05-02 | 2013-08-21 | 上海同臣环保有限公司 | Foldable screw type sludge dewatering machine with electroosmotic dewatering function |
SE539535C2 (en) * | 2013-11-07 | 2017-10-10 | Stora Enso Oyj | Process for dewatering a suspension comprising microfibrillated cellulose |
CN108915060A (en) * | 2018-07-09 | 2018-11-30 | 北京中岩大地科技股份有限公司 | A kind of dewatering of big scale of construction high-moisture low-permeability waste residue |
CN109734269A (en) * | 2019-02-28 | 2019-05-10 | 苏州高新北控中科成环保产业有限公司 | A kind of stage improvement method improving the saturating dewatering of sludge electroosmotic |
Family Cites Families (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NO139278C (en) * | 1967-04-05 | 1979-01-31 | Albany Felt Co | PAPER MACHINE FELT. |
GB1456721A (en) * | 1974-01-07 | 1976-11-24 | Acres Consulting Services | Electrophoresis and electro-osmosis in settlement and consoli dation of solid/fluid suspensions |
US4160711A (en) * | 1974-05-24 | 1979-07-10 | Marubishi Yuka Kogyo Kabushiki Kaisha | Assembly of electrodes |
DE2900868A1 (en) * | 1979-01-11 | 1980-07-24 | Kufferath Geb Gkd | WIRE RIBBON |
US4244804A (en) * | 1979-01-15 | 1981-01-13 | Innova, Inc. | Slime and sludge dewatering |
NZ193441A (en) * | 1979-04-21 | 1983-11-30 | Scapa Porritt Ltd | Link conveyor formed from plurality of helical coils |
DE2921491A1 (en) | 1979-05-26 | 1980-12-04 | T T Haaksbergen B V I O | METHOD FOR PRODUCING A LINKED BAND |
US4376022A (en) * | 1979-06-05 | 1983-03-08 | Battelle Memorial Institute | Method and apparatus for concentrating an aqueous sludge by electro-osmosis |
US4420529A (en) * | 1980-08-22 | 1983-12-13 | Scapa Dryers, Inc. | Anti-static dryer fabrics |
GB2083431B (en) * | 1980-09-06 | 1984-05-16 | Scapa Porritt Ltd | Link belts |
US4839213A (en) * | 1980-11-14 | 1989-06-13 | Cofpa | Conveyor belt constituted by plastic spirals |
CA1171382A (en) * | 1981-05-26 | 1984-07-24 | Alberta Oil Sands Technology And Research Authority | Electrophoretic process for separating aqueous mineral suspensions |
JPS58122085A (en) * | 1982-01-13 | 1983-07-20 | Mitsubishi Heavy Ind Ltd | Dehydrating method |
JPS5936507A (en) * | 1982-08-23 | 1984-02-28 | Oyama Kogyo Koutou Senmon Gatsukouchiyou | Continuous electroosmosis dehydrating equipment for sludge by beltconveying system |
DE3315696A1 (en) * | 1983-04-29 | 1984-10-31 | Württembergische Filztuchfabrik D. Geschmay GmbH, 7320 Göppingen | LINKED BAND, e.g. FOR PAPER PRODUCTION |
JPS60147209A (en) * | 1984-01-12 | 1985-08-03 | Fuji Electric Corp Res & Dev Ltd | Electrode of electroosmotic dehydrator |
DE3638036A1 (en) * | 1986-11-07 | 1988-05-11 | Siteg Siebtech Gmbh | SPIRAL LINK BAND WITH DIVIDED SPIRALS |
US5049248A (en) * | 1986-12-08 | 1991-09-17 | Battelle Memorial Institute | Liquid separation process for suspensions by a pulsating electrical current |
US4861496A (en) * | 1988-06-13 | 1989-08-29 | Recycled Energy, Inc. | Electro-dewatering method and apparatus |
US5114560A (en) * | 1989-08-28 | 1992-05-19 | Nagabhusan Senapati | Apparatus and method for removal of liquids |
ZA91538B (en) * | 1990-03-14 | 1991-11-27 | Csir | Electro-osmotic dewatering of sludges |
JP3141542B2 (en) * | 1992-07-07 | 2001-03-05 | 富士電機株式会社 | Electroosmotic dehydrator |
US5230809A (en) * | 1992-03-11 | 1993-07-27 | Donald Roslonski | Method and apparatus for dewatering sludge materials |
JP3298021B2 (en) * | 1992-12-10 | 2002-07-02 | 月島機械株式会社 | Electro-osmotic pressure dehydrator |
-
1994
- 1994-10-06 GB GB9420216A patent/GB9420216D0/en active Pending
-
1995
- 1995-09-22 AU AU35285/95A patent/AU3528595A/en not_active Abandoned
- 1995-09-22 US US08/809,940 patent/US5891342A/en not_active Expired - Lifetime
- 1995-09-22 WO PCT/GB1995/002255 patent/WO1996011051A2/en not_active Application Discontinuation
- 1995-09-22 DE DE69513675T patent/DE69513675T2/en not_active Expired - Lifetime
- 1995-09-22 EP EP95932099A patent/EP0784501B1/en not_active Expired - Lifetime
- 1995-09-22 BR BR9509034A patent/BR9509034A/en not_active IP Right Cessation
- 1995-09-22 JP JP8512401A patent/JPH10506839A/en active Pending
- 1995-09-22 CN CN95195494A patent/CN1076629C/en not_active Expired - Fee Related
- 1995-09-22 AT AT95932099T patent/ATE187097T1/en not_active IP Right Cessation
- 1995-09-22 CA CA002199389A patent/CA2199389A1/en not_active Abandoned
-
1997
- 1997-03-27 KR KR1019970701993A patent/KR970706055A/en not_active Application Discontinuation
- 1997-04-04 FI FI971426A patent/FI971426A0/en not_active Application Discontinuation
Also Published As
Publication number | Publication date |
---|---|
FI971426A (en) | 1997-04-04 |
DE69513675T2 (en) | 2000-06-15 |
EP0784501A2 (en) | 1997-07-23 |
WO1996011051A2 (en) | 1996-04-18 |
DE69513675D1 (en) | 2000-01-05 |
WO1996011051A3 (en) | 1996-06-20 |
US5891342A (en) | 1999-04-06 |
KR970706055A (en) | 1997-11-03 |
CN1076629C (en) | 2001-12-26 |
FI971426A0 (en) | 1997-04-04 |
GB9420216D0 (en) | 1994-11-23 |
BR9509034A (en) | 1998-06-23 |
JPH10506839A (en) | 1998-07-07 |
AU3528595A (en) | 1996-05-02 |
CA2199389A1 (en) | 1996-04-18 |
ATE187097T1 (en) | 1999-12-15 |
CN1159768A (en) | 1997-09-17 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0784501B1 (en) | Dewatering process | |
CN1190252C (en) | Apparatus for electrodewatering | |
US4101400A (en) | Method for dewatering sludge | |
ZA200602680B (en) | Dewatering treatment system and method | |
WO2016057392A1 (en) | Continuous electrokinetic dewatering of phosphatic clay suspensions | |
GB2294948A (en) | De-watering sludge/slurry by simultaneous mechanical compression and electro-osmosis using conductive belt | |
KR0137000B1 (en) | Electro-endosmosis type dehydrator | |
JPH0685845B2 (en) | Electro-osmotic dehydrator | |
KR970006504B1 (en) | Sludge dehydration apparatus | |
KR100815845B1 (en) | Electro-dewatering device for sludge using metal filter | |
JPH04126507A (en) | Sludge dehydrator | |
GB2065169A (en) | Electrocoagulation method and apparatus for dewatering of aqueous sludges | |
JPH0722660B2 (en) | Electro-osmotic dehydrator | |
KR100227126B1 (en) | Method of manufacturing conductible filter | |
AU2001254528B2 (en) | Apparatus for electrodewatering | |
SU1257058A1 (en) | Method of dewatering sewage sediments | |
KR100401982B1 (en) | The method of pressing sludge from steel making process | |
Kwiatkowski | Electrokinetic Treatment of Sludge | |
AU2001254528A1 (en) | Apparatus for electrodewatering | |
KR19990064655A (en) | Method of manufacturing conductible roller | |
MXPA00010644A (en) | Electrochemical device for purifying water |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 19970228 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE |
|
17Q | First examination report despatched |
Effective date: 19971016 |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY Effective date: 19991201 Ref country code: LI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 19991201 Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.SCRIBED TIME-LIMIT Effective date: 19991201 Ref country code: GR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19991201 Ref country code: ES Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY Effective date: 19991201 Ref country code: CH Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 19991201 Ref country code: BE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 19991201 |
|
REF | Corresponds to: |
Ref document number: 187097 Country of ref document: AT Date of ref document: 19991215 Kind code of ref document: T |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REF | Corresponds to: |
Ref document number: 69513675 Country of ref document: DE Date of ref document: 20000105 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20000301 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20000302 |
|
ET | Fr: translation filed | ||
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20000830 Year of fee payment: 6 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20000922 Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20000922 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY Effective date: 20000930 |
|
26N | No opposition filed | ||
NLS | Nl: assignments of ep-patents |
Owner name: VOITH FABRICS HEIDENHEIM GMBH & CO.KG;VOITH APPLET |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: MM4A |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20010922 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: IF02 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20010922 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 20070913 Year of fee payment: 13 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: AT Payment date: 20080916 Year of fee payment: 14 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20090401 |
|
NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee |
Effective date: 20090401 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20090922 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20100806 Year of fee payment: 16 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20120531 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20110930 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20130919 Year of fee payment: 19 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R119 Ref document number: 69513675 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20150401 |